The Foreign & Commonwealth Office has issued advice following bombings in both Cairo and Istanbul over the weekend.
On Sunday December 11 there was an explosion in a chapel next to the Coptic Christian cathedral in Abbaseya, Cairo, killing at least 20 people and injuring more than 40.
The FCO advises that visitors “remain vigilant” at all times and follow the advice of local security officials.
Egypt has declared three days of mourning following the bombing.
The country’s state-run news agency Mena reported that 12 kilograms of TNT explosives were used in the attack. The majority of those killed were women and children.
There was no immediate claim of responsibility for the attack.
In Turkey the death toll from twin bomb blasts outside the Besiktas football stadium in Istanbul on Saturday December 10 has risen to 38, including 30 police officers.
An offshoot group of Kurdish militant organisation the PKK – the Kurdistan Freedom Falcons, also known as TAK – has claimed responsibility for the blasts.
The FCO advises that visitors avoid the area, remain vigilant and follow the advice of the local security authorities.
The two bombs, a car packed with 300kg of explosives and a suicide bomb, struck at about 10.30pm.
At least 13 people have been arrested over the incidents.
The World Tourism Organization UNWTO said it was “deeply shocked” by the attack.
"On the behalf of the international tourism community, UNWTO conveys its heartfelt condolences to the families and friends of the victims and expresses its full solidarity with the people and the government of Turkey” said UNWTO secretary-general, Taleb Rifai.
“This attack reminds us once more that we are facing a global threat that requires us to work closer together to have a firm and coordinated response that engages all governments and the international community.
“Turkey is a leading tourism destination and we are confident it will continue to be so with the support of all.”
The World Travel & Tourism Council (WTTC) also condemned the attacks.
David Scowsill, president of WTTC, said: "Now more than ever it is important that public and private sectors work together to respond to the threats of terrorism.”